1. Field of the Invention
The present invention relates to an apparatus for verifying the wire gauges of a multi-core optical fiber and more particularly to an apparatus for verifying the coincidence between the input alignment order and the output alignment order of a multi-core optical fiber for use as an optical communication medium.
2. Description of the Related Art
A typical multi-core optical fiber is in the form of a tape which is made by aligning a plurality of optical fiber cores on a plane. The multi-core optical fiber requires that the input alignment order and the output alignment order should be coincident with each other. Assuming that these two sorts of order are not coincident, it is impossible to transmit an optical signal through any intended transmission line. However, verifying the coincidence between input and output wire gauges is required because an unsatisfactory product whose input alignment order and output alignment order are not coincident is produced at rare intervals in the stage of manufacturing multi-core optical fibers.
A conventional method of verifying the wire gauges of a multi-core optical fiber will be described With reference to FIG. 6. In FIG. 6, reference numeral 5 designates a light source; 12, an optical power meter; and 4, a multi-core optical fiber.
Each of the rays of output light from the multi-core optical fiber 4 has heretofore been measured with the optical power meter 12 by inputting the output of the light source 5 into each of the cores of the multi-core optical fiber 4 when the wire gauges of the multi-core optical fiber 4 are verified. For example, an input core numbered 1 is connected to the light source 5 and then the output of an output core numbered 1 is verified by the optical power meter 12.
It has been extremely troublesome to make preparations for measurement in the conventional method because the output side of the multi-core optical fiber 4 is separated into single cores and each of the cores is connected to the optical power meter 12 for measuring purposes and besides a great deal of measuring time has been necessitated. Moreover, there has been some possibility of making an error in verifying the wire gauges because the optical output of the output core is measured while the connection of the light source 5 to the input core is being switched.